Sakura Learns Something New
by Philosophical CAT
Summary: Between Wave and the chuunin exams, Sakura notices that Sasuke has a mysterious new medical seal and won't talk about what it does. That's fine, Sakura prefers to figure puzzles out for herself anyways. brief transphobia, trans!sasuke


All academy students were required to possess at least passing familiarity with the research library attached to the hospital. It was a regular matter to prepare for external missions by studying the plants, animals, and people local to the target region. Ninja were expected to be able to access and comprehend scholarly literature from a dozen fields of study in order to achieve the exacting standards of preparedness required by their work.

For many rookie genin such research was a much-loathed chore, but Sakura often found herself spending recreational time in the research library outside of missions. She read medical texts, civilian and ninja histories, chakra theory, seal theory; she was a voracious and omnivorous reader.

Today though, she had a particular goal in mind. Sasuke had acquired a seal-tattoo, and didn't seem inclined to talk about it. She didn't want to invade his privacy, but she reasoned to herself that it was a simple matter of mission-preparedness for her to be familiar with any sealwork that was actively impacting her teammates.

The seal was pretty obviously medical. All the central characters of its composition had relatively mundane medical roots. It altered the composition of the bloodstream by adding and filtering hormones; that much was easily uncovered by a basic medical sealing text. But the specifics were opaque to her.

The hormones involved didn't have simple representations in the seal characters, so she knew they weren't among the standbys of ninja medicine. That ruled out epinephrine, norepinephrine, and any growth hormones.

She eventually riddled out that multiple variants of testosterone were being captured as input by the seal's filtering logic, and being processed and reinserted. There weren't many useful metabolites of testosterone that she could find...and there remained another hormone that was being entirely synthesized within the seal itself; the incredible specificity necessary for such manufacturing accounted for more than half of the overall area of the seal.

The synthesis seal gave her an idea though. That portion of the seal was essentially just a description of the process for building a molecule, so she could follow that process on paper to reconstruct the atomic makeup and structure of the molecule and use that to figure out its name. That might give her a hint towards what the rest of the seal was for as well.

* * *

After much trial-and-error and a lengthy cross-referencing process, she determined that the mystery molecule was progesterone. The exercise had been more than a bit tedious, and she prided herself on being able to get a meaningful result at all--especially if it turned out to be correct.

But her result was puzzling. It immediately indicated that the mystery testosterone metabolites were estrogens of one kind or another, but that would mean the overall effect of the seal was to filter nearly all the testosterone out of the bloodstream and replace it with estrogens and progesterone. That was reasonably straightforward, but the _why_ of it all was deeply confounding her. Progesterone in particular was puzzling, as its primary roles in the body were to do with menstruation, pregnancy, and breast development, all of which presumably had little interest for a teenage boy.

A thought had been pounding insistently at her consciousness for a while now. A nonsensical thought that didn't seem to come from anywhere in particular. Sakura decided to turn her attention toward it, hoping it might leave her alone.

 _She's a girl you dipshit_

What? Rude.

 **Oh.**

* * *

"I think Sasuke is trying to be a girl." The words spilled out of her mouth not entirely within her control. She was certain that's not how she'd meant to word it, but she also couldn't figure out how better to say it.

"...and I turn to see Shikamaru laying down--what did you say?" Ino paused in the middle of her story to give Sakura a puzzled look. "Like trying to impersonate someone?"

"No like, there's a seal on his leg that seems like it's replacing his testosterone with female sex hormones. And he's being cagey but he doesn't seem worried about it, like he's trying to become a girl...I guess?"

Ino's eyes widened and she visibly recoiled. "Can...can you do that? Would that work? What would that even do? How do you even know?" the flood of questions built in intensity as she went on, before turning to Sakura with a somewhat accusing glare, "How do you know? Are you just making this up to get me to give up on him? Because I won't"

"I don't know know, but I spent all the past couple afternoons researching it in the library and I'm pretty confident…" With a bit of a huff, the pinkette added "And I wouldn't lie to you about this sort of thing. I'm gonna win fair and square, pig."

"But why? " Ino asked, almost pleading, "Why would he ruin his body like that? And seriously, what would that even do? It's not like he'll grow a…" she gestured toward her own groin, "Right?"

"I don't know why. I don't think anything would change...down there, but I don't know what effects this sort of thing would even have. They don't really write about this in regular textbooks, you know. I wouldn't even know how to start looking this kind of thing up. What if he does change all the way?" The last thought occurred to Sakura idly, but as she mused on it she could see a look of mild panic and disgust rising on Ino's face.

"Ew! I'm not a...a lesbian , forehead! Shit, if this is real, you can have him. Her. Whatever."

* * *

They'd dropped the conversation at that point, each lost in thought. Sakura left pretty quickly. She was a bit uncomfortable with Ino's attitude towards the news and unsatisfied with the amount of processing she'd gotten out of the conversation in the face of the blonde's strong reaction.

The thought occurred to her that Naruto was...weird in somehow the same way that Sasuke was starting to seem. Maybe the strange, boyish girl would have some insights into the situation.

* * *

She found the short-haired blonde sitting on a park bench with an effeminate man--it seemed she'd been a good judge of the kind of company her teammate kept--apparently lost in idle, friendly conversation. As she approached the man saw her and appeared to excuse himself. Naruto looked disappointed but not surprised. She waved him off sedately as Sakura reached the bench.

"Hi Sakura, how's it going? Oh damn, I'm not late for something am I?" Naruto seemed playfully defensive on this last point. Knowing her she probably wasn't actually sure.

"No, we still have the afternoon off. We're meeting as a team tomorrow, though. You remembered that, right?" The other girl nodded unconvincingly. Sakura rolled her eyes, but pivoted the conversation, "you don't know anything about the new seal on Sasuke's leg, do you?"

"The what?" The blonde seemed genuinely confused, and Sakura thought she'd be able to tell if she were hiding something.

With a sigh, Sakura explained herself. "I saw the seal while we were training last week. Sasuke didn't want to talk about it, so I drew as much of it as I could from memory...I think I got all of it down...and went to look it up in the library." Naruto seemed duly impressed, but impatient for her to get to the point. "I think it's turning his testosterone into estrogen and adding progesterone, and I think he's doing it on purpose." She averted her eyes as she finished, suddenly aware of the massive indiscretion it was to be sharing such half-baked theories, little better than gossip, about her teammate behind his back.

Thankfully, Naruto didn't seem to understand the significance of her accusation. "What's testosterone, and what's progesterone? But yeah, estrogen is what makes girls so...that way, right?" She gestured to her chest and hips somewhat crudely, and then made an exploding gesture around her head. "That makes sense."

Now it was Sakura's turn not to understand. "It makes sense? Testosterone is the hormone that controls masculine development, and progesterone controls, well periods mostly. How does that make sense? He's a boy!"

Somehow it seemed that Naruto had gained the upper hand in this conversation without Sakura noticing or realizing there was an upper hand to be had. "It makes sense 'cause Sasuke's a girl! Why would a boy want to get rid of his testosterone and replace it with girly stuff? Doesn't sound to me like something a boy would do. That seems like something a girl would do, if she found out her body was full of the wrong things."

Sakura wasn't sure that explanation completely checked out, but Naruto seemed to think she'd just been extremely clever and Sakura found she couldn't figure out what her disagreement was, exactly.

As she mulled over her response, Naruto's argument started to make a lot of sense. It didn't explain why Sasuke was a girl, but Sasuke being a girl in some intrinsic way certainly did bring a very satisfying logic to the situation. Besides, why was anyone a girl? And if she found herself in a boy's body, it'd certainly make her very uncomfortable. It was straightforward, in a bullheaded and circular way. She liked it.

* * *

It took her a while after leaving Naruto to find their teacher. She found him in a tree near one of the genin training grounds, pointedly ignoring a pair of ninja in matching green bodysuits sparring in a nearby clearing.

"Yo, Sakura! Are you planning on training this late in the day?" Kakashi called down to her without looking up from his book.

"I was looking for you actually, sensei." Sakura summoned a bit of courage to raise the subject a third time. She wasn't even sure why she wanted to talk to him about it, she just needed reassurance that everything was okay. And maybe a bit of praise for all her research and successfully solving the puzzle would be nice too. Not that Kakashi was the ideal place to look for praise.

"How can I help one of my adorable students this fine evening?" The vaguely condescending smile in his one eye was making Sakura doubt herself even more. She really shouldn't have expected talking to him to be any help.

"I just...I noticed a seal on Sasuke's leg and I wanted to," she closed her eyes and forced the stutter out of her voice, "I just wanted to make sure you knew about it and that everything was okay, Sir. It looks medical. I wanted to make sure my teammate isn't hurt, and that I'm aware and equipped to handle any peculiarities this seal might indicate." The unimpressed look on her Sensei's face pushed her into a halting, overly-formal cadence. Why couldn't he be just a tiny bit more personable?

Kakashi's face softened as he listened to her. "Ah, so you've noticed after all. Good work putting together that it's a medical seal, Sakura. And I suppose you'll have already figured out what it does?" He searched her face for a moment, apparently finding his answer there, "Sasuke is perfectly healthy, and I doubt that particular seal will bring up any mission-relevant trouble. I can't answer any of your other questions though, you'll have to talk to her yourself if you want answers."

Sakura was warmed a bit by the praise, though the last statement only tightened the anxious knot in her stomach. "So it's really that, huh? Okay, I'll go talk to," the slightest of pauses, "her."

Kakashi turned back to his book and waved her off. "She might not want to talk about it. This is going to be a very touchy conversation, and how you handle it will probably have lasting repercussions for your relationship. Be careful."

Swallowing nervously, Sakura nodded and left in the direction of Sasuke's house.

* * *

"Come in, there's tea for you." Sakura jumped slightly at the voice. Her fist had just been raised to knock at the door.

Sasuke looked tired and tense as she entered the small apartment. She kept the place impeccably neat, Sakura noticed. The only room aside from the bathroom and the kitchen was set with a low table and some cushions to sit on. There were two settings of tea and crackers at the table, the tea still steaming hot. Sasuke had been extremely prepared for her.

"Naruto told me you'd come by tonight. I kept the water on and started the tea steeping when I saw you down the road." Sasuke explained, seeing her bewildered look. She closed her eyes and sighed, resigned to the conversation ahead of her. "Why are you here, Sakura."

 _Why doesn't she ever actually ask questions?_

Sakura hesitated a moment before sitting, realizing she wasn't sure herself why she was here. "I figured out what that seal does, I think," she started, before changing tracks, "I told Ino about it. I'm sorry, I don't know why I did that...I was confused and didn't really...think of what it would mean. She uh, took it pretty badly. She'll probably tell other people. I'm so sorry." She was crying now. This wasn't what she'd thought she was going to say at all.

Sasuke too looked surprised, and not as upset as she'd feared. That was good, at least. "I told Naruto too, and Kakashi. But it seemed like they already knew so I'm sorry about those too but I don't think it'll have any consequences for you. Naruto says you're a girl." She looked up from her lap, where she'd been hiding her gaze from her teammate's patient glare. "Are you a girl?"

"That's what Naruto told me, too. It makes sense, in that nonsense way of hers. I don't really know if I'm a girl or what that even means, but I know that I have to do this." She gestured vaguely in a way that suggested the seal on her leg was only a small part of 'this', "I didn't have any choice, once I knew it was an option. I couldn't not do it. I guess that makes me a girl?" Sakura suspected that the present conversation was a part of the larger thing too.

"Okay," Sakura said with a gentle confidence that she didn't realize she felt. She was slightly surprised to realize that she meant it though. She really was okay with all this. "I love you."

The words had slipped out without her thinking, and she immediately regretted them. It was true, but it would do nothing to make Sasuke take her seriously, and wouldn't provide her with any comfort. The dark haired girl would just brush her off as a fangirl, whose affection was only lasting because it lacked enough depth to even care about something so significant as this.

Sasuke didn't look like she was going to brush her off though. The taller girl looked at her oddly, as though considering her in a new light for the first time. Then she scoffed and finished her cooling tea. "Sure. Was there anything else?"

Sakura could sense her welcome wearing thin, so she shook her head lightly and worked at the last of her tea. "No. I'll see you tomorrow morning."

On the way to the door she wondered if the conversation had gone well. As she exited, she saw the tired, pensive look on Sasuke's face. But she didn't look hurt, or sad, or resolved...she looked almost peaceful, as though an old tension had been lifted.

As she walked back to her parent's home, she began to feel the emotional exhaustion of the day catching up to her. When she reached her bed, she was asleep before her head hit the pillow.


End file.
